MANAGEMENT CONSIDERATIONS

SPECIES: Oplopanax horridus
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Devil's-club is not preferred by browsing animals, probably because of
its prickly leaves and stems. Black-tailed deer, white-tailed deer, and
elk utilize it lightly in spring and summer [29,45]; in one study, it
comprised an average of 3.4 percent of the summer diet of Roosevelt elk
at widely distributed sites on the Pacific Northwest Coast [32]. Moose
on Isle Royale, Michigan do not browse it [46].
Devil's-club growing on banks of stream channels provides shade cover
for salmonoid fishes and their eggs. Bear prefer such areas because of
the readily available sources of fish and devil's-club berries [14].
Grizzly and black bear also consume devil's-club seeds, leaves, and
stems [4,26,33,37].
PALATABILITY :
NO-ENTRY
NUTRITIONAL VALUE :
Mean value of in-vitro dry-matter digestibility of devil's-club for
white-tailed deer is 73.3 percent for leaves and 53.7 percent for stems.
Percentage composition of macro- and micronutrients in devil's-club
leaves and stems are available [29].
COVER VALUE :
Devil's-club provides hiding, escape, and thermal cover for various
birds, rodents, and the vagrant shrew [31].
VALUE FOR REHABILITATION OF DISTURBED SITES :
NO-ENTRY
OTHER USES AND VALUES :
Devil's-club is planted as an ornamental [34,45].
OTHER MANAGEMENT CONSIDERATIONS :
NO-ENTRY

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Oplopanax horridus
GENERAL BOTANICAL CHARACTERISTICS :
Devil's-club is a native, erect to slightly spreading, deciduous shrub
from 3.3 to 10 feet (1-3 m) in height. It is sparsely branched with
sharp, dense prickles on stems and prominent leaf veins [24,30,48]. The
fruit is a drupe with two to three seeds [23,48]. Cooper and others
[11] noted that this species is rhizotomous; other researchers have yet
to confirm this. Devil's-club is drought intolerant [10].
RAUNKIAER LIFE FORM :
Phanerophyte
REGENERATION PROCESSES :
Information on devil's-club regeneration is scant. Seedling growth is
apparently slow [34]. Devil's-club reproduces vegetatively, but the
method is uncertain. Vegetative reproduction may be accomplished by
rhizomes [11] and/or layering [34]. Stickney [42] tentatively listed it
as a root crown sprouter.
SITE CHARACTERISTICS :
Devil's-club is a wet-site indicator [38]. It grows on moderately
well-drained to poorly drained, shaded sites. It is commonly found near
springs and streams and in drainage, seepage, and wet bottom areas
[5,8,27]. It occurs on variable aspects [9], growing in soils that are
sandy, loamy, or silty in texture. Devil's-club-supporting soils are
sometimes skeletal. Soils are derived from quartzite or from fluvial,
colluvial, glaciolacustrine, or morainal deposits [11,6,27]. Soil pH is
acid. It ranges from 4.5 to 6.0 in the western redcedar/devil's-club
type of northern Idaho [11], and was measured at 3.8 in the Sitka alder
(Alnus viridis spp. sinuata)/devil's-club type of southern Alaska [39].
Soil nutrient levels are medium to very rich [24]. Climate varies from
maritime, submarine, and continental types [24]. Elevational ranges for
devil's-club in several locations are as follows:
feet meters
northwestern Montana 3,900-5,000 1,189-1,524 [8]
Oregon 1,300-4,600 396-1,402 [9,25]
northern Idaho 1,500-4,900 460-1,495 [11]
southeastern Alaska 0-1,700 0- 518 [14,47]
SUCCESSIONAL STATUS :
Devil's-club is moderately shade tolerant [24] and is primarily found in
understories of late seral, climax, and old-growth forests. Best growth
is attained in climax (mature) forests [6,8]. Average devil's-club
biomass at widely located sites in western hemlock-western redcedar and
Sitka spruce-western hemlock forests of southeastern Alaska was as
follows [3]:
clearcut sites: 0.00 lb/acre
young (30- to 100-year-old): 0.09 lb/acre (0.1 kg/ha)
mature (100- to 250-year old): 4.80 lb/acre (5.4 kg/ha)
old-growth (250+ years): 2.90 lb/acre (3.3 kg/ha)
SEASONAL DEVELOPMENT :
Devil's-club flowers in late spring to midsummer, depending upon
location. Plants in southeastern Alaska bloom in June [45], while
plants on the Lake Superior islands bloom in mid-July. Fruits ripen
approximately 4 weeks after flowering and persist over winter [46].
Leaves are dropped within a few days of the first fall frost. In the
Cascade Range of Oregon, leaf abscission occurs in October or November
[10].

FIRE ECOLOGY

SPECIES: Oplopanax horridus
FIRE ECOLOGY OR ADAPTATIONS :
Sites where devil's-club occurs burn infrequently. Wildfire is uncommon
in various forest-devil's-club types of southeastern Alaska [28].
Typically, the moist ravines and streamside areas serve as a fire break
to low- and moderate-severity ground fires. The return interval for
such fires ranges from 50 to 100 years in the western redcedar/devil's
club type of western Montana. Less often, this type undergoes severe,
stand-replacing fire, regressing the site to pioneer conditions.
Stand-replacing fires in the western redcedar/devil's-club type of
western Montana have historically occurred at intervals ranging from 150
to more than 500 years [13].
Devil's-club adaptations to fire are not well documented. It may sprout
from the root crown [18,42]. Sprouting from rhizomes may also occur [11].
POSTFIRE REGENERATION STRATEGY :
NO-ENTRY

FIRE EFFECTS

SPECIES: Oplopanax horridus
IMMEDIATE FIRE EFFECT ON PLANT :
Devil's-club is susceptible to fire-kill [18], but its susceptibility by
class of fire severity is unknown.
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
NO-ENTRY
PLANT RESPONSE TO FIRE :
Postfire recovery of understory species, presumably including devil's
club, in forest/devil's-club types of British Columbia is more rapid
than in other forest types. Researchers credit this to the generally
lower fire intensity. Devil's-club frequency at widely scattered sites
in British Columbia that had burned less than 10 years prior to sampling
was from 61 to 80 percent [27].
Extrapolating from Alaback's [3] data (see Successional Status), devil's
club is probably absent from burn sites for decades following
stand-replacing fire. Presumably, devil's-club establishes on these
sites from animal-dispersed seed after the canopy has closed enough to
shade this light-sensitive species.
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
Hamilton's Research Papers (Hamilton 2006a, Hamilton 2006b) provide
information on prescribed fire and postfire response of plant species,
including devil's-club, that was not available when this species review
was originally written.
FIRE MANAGEMENT CONSIDERATIONS :
Overall fire potential is rated as low in western redcedar/devil's-club
habitat types of western Montana [17].